Apparatus for controlling space between head and medium

a technology for controlling the space between the head and the recording medium, which is applied in the direction of data recording, magnetic recording, instruments, etc., can solve the problems of head and the medium coming into contact with each other, excessive protruding the pole section, and difficult to practice the system

Inactive Publication Date: 2008-11-25
TOSHIBA STORAGE DEVICE CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

"The present invention provides an apparatus for controlling the space between a recording medium and a head for accessing data recorded on the medium. The apparatus includes a voltage applying unit that applies a voltage to a plurality of capacitors formed in series by the recording medium and electrode plates on the head, and a space control unit that controls the space between the head and the recording medium based on the response of the capacitors to the voltage. This technology solves the problem of conventional technology where the space between the recording medium and the head cannot be controlled effectively."

Problems solved by technology

However, in the feed-forward control, when a fluctuation in manufacturing, a change in the atmospheric pressure, or a temperature change occurs, which causes the levitation amount of the head to be dynamically changed, it is likely that the magnetic pole section excessively protrudes, making the head and the medium come into contact with each other.
However, in the system disclosed in the conventional technology, it is necessary to ground the medium using some sort of method, making it difficult to practice the system.

Method used

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  • Apparatus for controlling space between head and medium
  • Apparatus for controlling space between head and medium
  • Apparatus for controlling space between head and medium

Examples

Experimental program
Comparison scheme
Effect test

first embodiment

[0050]FIG. 3 is a functional block diagram of the constitution of the magnetic disk device according to the present invention. Components of a magnetic disk device 200 identical with those of the magnetic disk device 100 shown in FIG. 1 are denoted by the identical reference numerals and signs. Explanations of the components are omitted.

[0051]The magnetic disk device 200 according to the first embodiment includes the medium 10, a head 210, an AC-voltage generating circuit 220, a detecting circuit 230, and a control unit 240. The head 210 includes the electrode plates 20a and 20b and a resistor 211. It is possible to consider that the electrode plate 20a and the medium 10 form the capacitor 25a, the electrode plate 25b and the medium 10 form the capacitor 25b, and the capacitors 25a and 25b are capacitors connected in series. The resistor 211 is an electric resistor for an electric current flowing through the head 210.

[0052]The AC-voltage generating circuit 220 includes an AC voltage...

second embodiment

[0070]A magnetic disk device 400 shown in FIG. 7 according to the present invention periodically applies a step voltage to capacitors connected in series by a medium and a head and controls a space between the medium and the head based on a response (a time constant) of the capacitors to which the step voltage is applied.

[0071]In this way, the magnetic disk device applies a step voltage to the capacitors instead of an AC voltage and controls a space between the medium and the head based on a response of the capacitors to which the step voltage is applied. This makes it possible to accurately control a space between the medium and the head. Further, since a circuit is simplified, it is possible to reduce cost of the entire magnetic disk device.

[0072]The magnetic disk device 400 according to the second embodiment includes the medium10, the head 210, a step-voltage generating circuit 410, a detecting circuit 420, and a control unit 430. Components of the magnetic disk device 400 identi...

third embodiment

[0082]A magnetic disk device 500 shown in FIG. 9 according to the present invention controls a voltage inputted to capacitors and control a space between a medium and a head by changing resistances of variable resistors connected to both sides of the capacitors.

[0083]The magnetic disk devices according to the first and the second embodiments need to directly adjust a magnitude of a voltage output from the voltage generator when a space between the medium and the head is controlled. However, the magnetic disk device according to the third embodiment only has to change resistances of the resistors connected to the capacitors. Thus, it is possible to simplify a circuit and reduce cost of the magnetic disk device.

[0084]The magnetic disk device 500 according to the third embodiment includes the medium 10, a head 510, a signal generating circuit 520, a detecting circuit 530, and a control unit 540. Components of the magnetic disk device 500 identical with those of the magnetic disk device...

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Abstract

A voltage applying unit applies a voltage to a plurality of capacitors respectively formed in series by the recording medium and a plurality of electrode plates arranged on the head. A space control unit controls a space between the recording medium and the head based on a response of the capacitors to the voltage applied by the voltage applying unit.

Description

BACKGROUND OF THE INVENTION[0001]1. Field of the Invention[0002]The present invention relates to a technology for controlling a space between a head and a recording medium with a capability of controlling levitation amount of the head using electric characteristics between the head and the medium even when the medium is electrically isolated from a ground.[0003]2. Description of the Related Art[0004]In recent years, with an increase in a recording density of a magnetic disk of a magnetic storage device, it is desired to control levitation amount of a head to keep a space between the head and a medium as small as possible. As a control for the levitation amount of the head implemented today, for example, a feed-forward control arranges a heater on the head for heating the head to protrude a magnetic pole section for recording and reproducing data to the medium.[0005]However, in the feed-forward control, when a fluctuation in manufacturing, a change in the atmospheric pressure, or a t...

Claims

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Application Information

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Patent Type & AuthorityPatents(United States)
IPC IPC(8): G11B21/02
CPCG11B5/6017
InventorMATSUSHITA, HIROKI
OwnerTOSHIBA STORAGE DEVICE CORP